scholarly journals Effect of Cu Ions Implantation on Structural, Electronic, Optical and Dielectric Properties of Polymethyl Methacrylate (PMMA)

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 973
Author(s):  
Athar N. Akhtar ◽  
G. Murtaza ◽  
M. Ahsan Shafique ◽  
Ahmed S. Haidyrah
Keyword(s):  
Dielectric Constant ◽  
Energy Gap ◽  
Electronic Devices ◽  
Ultra Violet ◽  
Pristine Sample ◽  
Xrd Study ◽  
Wide Energy ◽  
Lower Variation ◽  
Cu Ions ◽  
Potential Use

In this work, the effect of ion bombardment on the optical properties of Polymethylmethacrylate (PMMA) was studied. Polymer samples were implanted with 500 keV Cu+ ions with a fluence ranging from 1 × 1012 to 1 × 1014 ions/cm2. X-ray Diffractometer (XRD) study indicated a relatively lower variation with a higher dose of ions. Fourier Transform Infrared (FTIR) spectra exhibited that with the implantation of Cu ions the intensity of existing bands decreases, while the result confirms the existence of a C=C group. The pristine and ion-implanted samples were also investigated using photoluminescence (PL) and Ultra Violet-Visible (UV-VIS) spectra. The optical band gap (Eg) was observed up to 3.05 eV for the implanted samples, while the pristine sample exhibited a wide energy-gap up to ~3.9 eV. The change in the optical gap indicated the presence of a gradual phase transition for the polymer blends. The dielectric measurements of the pristine and Cu-implanted PMMA were investigated in the 10 Hz to 2 GHz frequency range. It was found that the implanted samples showed a significant decrease in the value of the dielectric constant. The value of the dielectric constant and dielectric loss of the PMMA and Cu-implanted samples at a 1-kHz frequency were found to be ~300 and 29, respectively. The modification of the PMMA energy bandgap in the current research suggested the potential use of Cu implanted PMMA in the field of optical communications and flexible electronic devices.

scholarly journals Empirical Relation for Electronic and Optical Properties of Binary Tetrahedral Semiconductors

2021 ◽  
Keyword(s):  
Dielectric Constant ◽  
Optical Properties ◽  
Atomic Number ◽  
Energy Gap ◽  
Empirical Relation ◽  
Average Energy ◽  
Optical Parameters ◽  
Dielectric Analysis ◽  
Average Atomic Number ◽  
Tetrahedral Semiconductors

The concept of ionicity has been developed by Phillips and Van Vechten from the dielectric analysis of the semiconductors and insulators to evaluate various bond parameters of binary tetrahedral (AIIBVI and AIIIBV) semiconductors. In this paper, an advance hypothesis of average atomic number of the elements in a compound has been used to evaluate intrinsic electronic and optical parameters such as ionic gap (Ec), average energy gap (Eg), crystal ionicity (fi) and dielectric constant (ϵ) of binary tetrahedral semiconductors.

scholarly journals Análisis cristalográfico, morfológico, eléctrico, óptico y magnético del nuevo material Dy2BiFeO6

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Jairo Roa-Rojas
Keyword(s):  
Dielectric Constant ◽  
Energy Gap ◽  
Magnetic Hysteresis ◽  
Magnetic Ordering ◽  
Relative Dielectric Constant ◽  
Double Perovskite ◽  
Crystallographic Analysis ◽  
Weiss Temperature ◽  
Constant E ◽  
Diffraction Patterns

We report structural analysis, surface morphology, magnetic ordering, dielectric response, optical feature and the electronic structure of the Dy2BiFeO6 novel complex perovskite. The samples were produced by the standard solid-state reaction recipe. Crystallographic analysis was performed by Rietveld refinement of experimental X-ray diffraction patterns. Results show that this material crystallizes in a perovskite with orthorhombic structure, which corresponds to the Pnma (#62) space group. From the Curie-Weiss fitting on the curve of susceptibility as a function of temperature we establish that the ordering corresponds to a paramagnetic-antiferromagnetic transition, with a Weiss temperature q=-18,5 K, which is compatible with the behavior of the inverse of susceptibility as a function of temperature, and a Néel temperatura TN=50,8 K. The Curie constant allowed for us to obtain an effective magnetic moment of 15,7 mB. The result of magnetization as a function of the applied field, measured at T=50 K, shows a magnetic hysteresis behavior that corroborate the magnetic ordering present for this temperature value. Measurements of the dielectric constant as a function of applied frequencies at room temperature give as a result a high relative dielectric constant (e=780). The reflectance curve as a function of the wavelength reveals the typical behavior of a double perovskite-like material and permits to obtain the energy gap 2,74 eV, which is characteristic of a semiconductor material.

Energy gap and optical dielectric constant of Pb1−Cd Se films

1987 ◽  
Vol 27 (6) ◽  
pp. 389-397 ◽  
Author(s):  
M. Baleva ◽  
M. Maksimov ◽  
M. Sendova
Keyword(s):  
Dielectric Constant ◽  
Energy Gap ◽  
Optical Dielectric Constant ◽  
Optical Dielectric

scholarly journals Estimation of optical parameters of silicon single crystals with different orientations

2019 ◽  
Vol 37 (1) ◽  
pp. 65-70
Author(s):  
M.M. El-Nahass ◽  
H.A.M. Ali
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Single Crystals ◽  
Energy Gap ◽  
Optical Parameters ◽  
Dispersion Energy ◽  
High Frequency Dielectric Constant ◽  
Single Oscillator Model ◽  
Indirect Allowed Transition ◽  
Single Oscillator

AbstractOptical properties of Si single crystals with different orientations (1 0 0) and (1 1 1) were investigated using spectrophotometric measurements in a spectral range of 200 nm to 2500 nm. The data of optical absorption revealed an indirect allowed transition with energy gap of 1.1 ± 0.025 eV. An anomalous dispersion in refractive index. The normal dispersion of the refractive index was discussed according to Wemple-DiDomenico single oscillator model. The oscillator energy Eo, dispersion energy Ed, high frequency dielectric constant ∈∞, lattice dielectric constant ∈L and electronic polarizability αe were estimated. The real ∈1 and imaginary ∈2 parts of dielectric constant were also determined.

Symmetric “Double Spiro” Wide Energy Gap Hosts for Blue Phosphorescent OLED Devices

2021 ◽  
pp. 2101530
Author(s):  
Jie Ma ◽  
Muazzam Idris ◽  
Tian Y. Li ◽  
Daniel S. M. Ravinson ◽  
Tyler Fleetham ◽  
...  
Keyword(s):  
Energy Gap ◽  
Wide Energy ◽  
Blue Phosphorescent

Investigation of Cubic PbS/AgSbS2 System for Thermoelectric Applications

2007 ◽  
Vol 1044 ◽  
Author(s):  
Iliya Todorov ◽  
Duck-Young Chung ◽  
Mercouri Kanatzidis
Keyword(s):  
Melting Point ◽  
Energy Gap ◽  
Variable Temperature ◽  
Thermal Power ◽  
High Melting ◽  
Conductivity Data ◽  
High Melting Point ◽  
Solar Thermal Power ◽  
Wide Energy ◽  
Solar Thermal Power Generation

AbstractInvestigation of a family of bulk cubic compounds with general formula AgPbmMS2+m (M = Sb, Bi) is reported. These PbS-based cubic structured quaternary systems combine a set of desirable features for efficient ZT thermoelectric materials for solar thermal power generation. AgPbmMS2+m (M = Sb, Bi) possess an average NaCl structure (Fm-3m symmetry), high melting point (991 - 1095 °C for M = Sb; 865 - 1091 °C for M = Bi), relatively wide energy gap (0.7 > Eg (eV) > 0.39 for both Sb and Bi). The systematic variation of lattice parameters, energy gap and melting point is reported. Preliminary charge transport properties are reported along with variable temperature thermal conductivity data of selected members.

Characterization and Aging Test Methodology for Power Electronic Devices at High Temperature

2011 ◽  
Vol 324 ◽  
pp. 411-414 ◽  
Author(s):  
Ali Ibrahim ◽  
Zoubir Khatir ◽  
Laurent Dupont
Keyword(s):  
High Temperature ◽  
Energy Gap ◽  
Switching Frequency ◽  
Power Electronic ◽  
Active Components ◽  
Ambient Temperatures ◽  
Test Methodology ◽  
Aging Test ◽  
Wide Energy ◽  
Strategic Issue

Power electronic modules are key elements in the chain of power conversion. The application areas include aerospace, aviation, railway, electrical distribution, automotive, home automation, oil industry ... But the use of power electronics in high temperature environments is a major strategic issue in the coming years especially in transport. However, the active components based on silicon are limited in their applications and not suitable for those require both high voltages and high ambient temperatures. The materials with wide energy gap like SiC, GaN and diamond, have the advantage of being able to exceed these limits [1,2]. These materials seem adequate to extremely harsh temperature environments and allow the reduction of cooling systems, but also the increasing of switching frequency.

The Structural Stabilities and Electronic Properties of Orthorhombic and Rhombohedral LaCrO3 — A First-Principles Study

2012 ◽  
Vol 622-623 ◽  
pp. 734-738
Author(s):  
Qing Gong Song ◽  
Ling Ling Song ◽  
Hui Zhao ◽  
Tong Wei ◽  
Jian Hai Kang
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Ceramic Materials ◽  
Binding Energies ◽  
Nano Materials ◽  
Functional Theory ◽  
Self Consistent Field ◽  
Wide Energy ◽  
Equilibrium Structures

The equilibrium structures of orthorhombic LaCrO3(O-LaCrO3) and rhombohedral LaCrO3(R-LaCrO3) crystals were investigated by using the plane-wave self consistent field (PWSCF) method based on density functional theory (DFT). The optimized lattice parameters for both phases are in accordance with experimental results reported in literature, confirming the reliability of LSDA+U scheme used in the calculations. We have quantificationally investigated the binding energies and electronic properties of these two types of LaCrO3crystals. The negative total energy and binding energies indicate the ground state property and the good structrual stability of O-LaCrO3crystal, which is important for the preparation of nano materials, the synthesis of ceramic materials made of doped O-LaCrO3crytals, as well as their applications in high technology fields, and predict the metastable property of R-LaCrO3crystal. Furthermore, the band structures show that O-LaCrO3is a direct semiconductor with wide energy gap, while R-LaCrO3is an indirect semiconductor with narrow energy gap. The interaction between Cr and O atoms in O-LaCrO3crystal possesses the character of covalent bonding.

Two-dimensional Au lattices featuring unique carrier transport preference and wide forbidden gap

Nanoscale ◽  
2014 ◽  
Vol 6 (17) ◽  
pp. 10118-10125 ◽  
Author(s):  
Chunmiao Zhang ◽  
Yaping Wu ◽  
Yinghui Zhou ◽  
Na Gao ◽  
Fei Guo ◽  
...  
Keyword(s):  
Large Scale ◽  
Carrier Transport ◽  
Energy Gap ◽  
Two Dimensional ◽  
Wide Energy ◽  
Forbidden Gap

Large-scale 2D Au lattices are achieved that display a unique wide energy gap and a Kagome-like transport route.

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